1. Field of the Invention
The present invention relates to a surgical stapling and cutting instrument adapted for use in the diagnosis and therapy of pathologies treated by curved stapled resection. More particularly, the invention relates to a lockout mechanism for utilization in conjunction with surgical stapling and cutting instruments.
2. Description of the Prior Art
Surgical stapling and cutting instruments are commonly utilized in the diagnosis and treatment of pathologies treated by stapled resection. Surgical stapling and cutting instruments provide a mechanism to extend the transluminal exploitation of mechanical suturing devices introduced via the anal canal, mouth, stomach and service accesses. Although surgical stapling and cutting instruments are most commonly utilized with rectal pathologies, surgical stapling and cutting instruments may be used in a variety of environments.
Over time, surgical stapling and cutting instruments have been developed. These instruments generally include a support frame, an anvil attached to the support frame and a cartridge housing carrying a plurality of staples. The instruments also include a driver within the cartridge housing which pushes all of the staples out simultaneously into the anvil to form the staples into a generally B-shape, suturing tissue together. In addition, these instruments include approximation mechanisms that allow for the cartridge housing and anvil to move relative to each other to accept tissue therebetween. Finally, the instruments include a firing mechanism for moving the driver forward to form the staples against the anvil.
In addition to the basic components of the stapling and cutting instruments, these products need a lockout mechanism permitting activation and/or deactivation of the approximation means such that the cartridge module may be utilized as a clamp when needed during an emergency. However, the lockout mechanism is designed such that the firing mechanism only works for a cartridge module that has not been previously used.
Current surgical stapling instruments include a firing bar lockout that is activated by the driver. When a new cartridge module is loaded into the instrument, the location of the driver, as it relates to the cartridge module in the instrument, interferes with the lockout arm in a way as to let the instrument fire staples. After the instrument fires staples, the location of the driver moves distally in a way that it no longer interferes with the lockout arm. The lockout arm rotates to a position that now interferes with the firing bar, but prevents the firing bar from moving distally.
In addition, prior lockout mechanisms provide no means for determining whether the lockout has been activated or whether the instrument is simply jammed. These lockout mechanisms merely prevent movement of the instrument in a manner that would be similar to a jammed instrument.
As such, a need exists for an improved lockout mechanism that provides for the activation and/or deactivation of the approximation mechanism to ensure that clamping may only be performed with an unused cartridge module. In addition, the prior art mechanisms fail to provide a tactile feedback feature that warns a user the device is locked out and not jammed. The present invention provides such a lockout mechanism. In fact, the present device provides for partial reapproximation that functions to provide the user with tactile feedback that the device is locked out, not jammed as may be the feedback from current devices.